Enduro Bearings Enduro XD-15 Ball Bearing Set - Shimano GRX - 11 Speed

BKCJ - 0351 - 11/13 teeth, XD15 ceramic hybrid bearing, machined Delrin derailleur pulleys for Shimano GRX 11 speed derailleurs (5mm bolt hole). The ultimate upgrade pulley. Lifetime warranty against corrosion. Precision machined Delrin derailleur pulleys with XD15 Ceramic - Hybrid radial bearings for increased shifting performance and longevity. Designed and engineered for performance, these pulleys feature CN (low-backlash) bearings in the upper pulley to maximize shifting accuracy and C4 (low-backlash) bearings in the lower pulley to allow chain movement. Delrin 500 AF, the material of the pulleys, has high mechanical tensile strength and stiffness, natural lubricity, high resistance to moisture, caustic chemicals and UV, making these pulleys very durable, stiff and smooth. Delrin also machines very cleanly and accurately. The inherent lubricating qualities of this Teflon-infused material greatly reduce friction when in contact with the bicycle chain. Compared toautres pulley materials, Delrin 500 AF with Teflon offers significantly less resistance than machined aluminum or titanium pulleys. Exclusive toEnduro Bearings, our XD15 Ceramic - Hybrid bearings combine corrosion-resistant, cryogenically treated nitrogen steel rings with Grade 3 silicon nitride ceramic balls in a proprietary process that results in an optimal high-performance bearing configuration. The deep groove raceways allow the use of maximum size grade 3 silicon nitride ceramic balls, increasing contact area and improving performance and life. Kluber NBU52 90% filled grease only gets better and smoother over time and is very resistant to washing. It is designed to adhere to the balls and be continually returned to the ball path where it is needed.
. The size and profile of the eleven-tooth top pulley and twelve-tooth bottom pulley, with 5mm bolt holes, are designed as an upgrade for most 11-speed Shimano GRX derailleurs. Enduro derailleur pulleys are available in a number of configurations and performance levels and are all proudly made with precision in the USA.